A prior art discloses such a vehicular machine available for transplanting vegetal seedlings onto plural seedbed lines, which consists of those components mounted on a working truck hauled by a tractive vehicle including the following; a seedling mounting table, a plurality of planting levers for simultaneously transplanting those vegetal seedlings mounted on the table onto multiple seedbed lines, and a working step which is provided on a working truck to permit a seedling-replenishing operator to mount on it so that he can sequentially replenish vegetal seedings onto the seedling mounting table containing decreased amount of vegetal seedlings.
Nevertheless, such a conventional vehicular machine available for transplanting vegetal seedlings onto multiple seedbed lines cited above still has problems to solve including the following:
The first problem is caused by the structure of the working truck which is easily movable in the vertical direction. Generally, vegetal seedlings are planted on such wide and plane field which is roughly plowed by operating a vehicular machine for transplanting vegetal seedlings like the one cited above. Since the working truck is obliged to follow up rolling on unlevelled ground surface, the working step constantly swings itself, thus obliging the seedling replenishing operator to follow up the replenishing work with unstable posture. Furthermore, since the operating system is designed to control pitching and rolling of the planting unit based on the level of the working truck, vegetal seedlings cannot properly be transplanted with constant depth.
The second problem is caused by excessively high position of the working step. Normally, a transmission shaft is disposed below the working step in order to transmit drive force from the front part of the working truck to the planting unit. Nevertheless, in order to align the height of the PTO shaft of the tractive vehicle with the height of the drive-power receiving unit of the working truck, the conventional vehicular machine cited above installs the working step at such a height position relatively aloft from the ground surface. In consequence, operator inconveniently mounts and dismounts himself on and from the working step, and yet, the height position of the seedling mounting table is too low from the operator's seat on the working step. As a result, the operator incurs much inconvenience when replenishing vegetal seedlings to the mounting table.
The third problem is caused by those reasons cited below. The owner of the vehicular machine in subject is likely to make use of a conventional general-purpose tractor owned by himself as the tractive vehicle. In this case, since the speed range of those conventional general-purpose tractors differs from each other according to manufacturers and models, if the operator drives the planting unit with drive force output from the PTO shaft of a conventional tractor, then, the speed of the tractor cannot correctly match the number of the rotation of the drive shaft of the planting unit, and in consequence, constant intervals between planted vegetal seedlings cannot be secured. Likewise, if gears of the PTO shaft were incorrectly shifted, those vegetal seedlings cannot properly be transplanted at constant intervals.
The forth problem is caused by those reasons cited below. The planting unit of the above conventional vehicular machine available for transplanting vegetal seedlings has the structure described below. Concretely, the seedling mounting table is installed with slight incline so that the front end can be positioned slightly higher than the rear part. Using a seedling conveying belt, those vegetal seedlings on the mounting table are sequentially delivered to an outlet at the rear end of the planting unit. Then, those plural planting levers respectively transplant vegetal seedlings delivered via the rear outlet while vertically moving themselves according to the predetermined rule. Nevertheless, since these planting levers are positioned behind the seedling outlet, those vegetal seedlings on the mounting table and pot holders (available for holding those seedling-receivers) at the rear end of the seedling mounting table respectively obstruct the operator on the working step to check and confirm if those planting levers are on still posture, or not.
The fifth problem is caused by the function of the seedling conveying belt provided for the seedling mounting table. The seedling conveying belt is engaged with a pair of seedling forwarding rollers comprising a drive roller and a follower roller. As soon as the seedling mounting table arrives at the end of the travelling path by way of reciprocating itself in both directions, those seedling forwarding arms secured to the shafts of the drive-side seedling forwarding roller are rotated in the predetermined direction, and then, the seedling conveying belt moves in the direction of forwarding vegetal seedlings. Actually, a plurality of seedling forwarding rollers on the drive side corresponding to respective seedbed lines are jointly secured to a roller shaft so that all the seedling forwarding belts corresponding to respective seedbed lines can simultaneously rotate themselves.
Nevertheless, it is necessary for the operator to properly adjust positions of all the vegetal seedlings on the way of replenishing them so that no clearance can be generated between those vegetal seedlings which still remain on the mounting table and the replenished vegetal seedlings. Furthermore, if any trouble occurs while those planting levers respectively pick up vegetal seedlings, then the operator needs to properly adjust the positions of vegetal seedlings on the mounting table. If the operator ever displaces the position of vegetal seedlings by carelessly operating any of these seedling forwarding arms, then those vegetal seedlings on the remaining normal seedbed lines are also improperly displaced, thus adversely obstructing the seedling forwarding operation.
The sixth problem arises from such a conventional vehicular machine available for tranplanting vegetal seedlings on multiple seedbed lines. When operating this conventional vehicular machine by installing a plurality of planting units to the front and to the back in order to prevent the adjoining planting units from interfering with each other, since each plant unit terminates the operation to plant those vegetal seedlings at different positions, after completing the whole planting operations, a blank domain devoid of seedling is generated in those seedbed lines corresponding to those planting units disposed in the front of the vehicular machine.